Exercise body surface mapping in patients with left ventricular hypertrophy: comparison with stress thallium scans...

To evaluate exercise-induced myocardial ischemia in patients with electrocardiographic evidence of left ventricular hypertrophy (LVH), including ST.T changes, body surface maps (QRST area maps) were recorded using 87 lead points before and after exercise. The patterns of the subtraction QRST area maps (S-maps) were compared with the findings of stress thallium (T1) scans in 31 patients with hypertrophic cardiomyopathy and in five with essential hypertension. All 18 patients whose S-maps revealed changes less than -40 muVS or only an increase over the anterior chest region showed no positive findings on the stress T1 scans. However, there were clearly positive findings on stress T1 scans in eight (89%) of nine patients whose S-maps revealed changes greater than -40 muVS over a wide precordial region or in six (67%) of nine patients whose S-maps revealed increases over the anterior chest region and had accompanying changes greater than -40 muVS somewhere over the precordial region. These results suggested that exercise QRST area maps could differentiate exercise-induced myocardial ischemia from LVH with ST.T changes.